CRYSTENGCOMM
·
2014
·Vol. 16
·期 37
·8910-8916
·
IF 3.858
Feng Ye,Hui Liu,Wenlai Huang,Jun Yang
Controlling the morphology of noble metal nanoparticles can be an effective way to produce nanomaterials with favourable properties. Herein, we report our study on the effects of diffusion rate and reaction kinetics on the morphology of a number of noble metal (Au, Ag, Pd, and Pt) nanoparticles. A glass reactor based on electrochemical reduction or photo-reduction has been designed to achieve control of diffusion and chemical reduction of the different noble metal precursors. The results show that the noble metal nanoparticles with flower-like, core–shell, or wheel-like morphologies could be obtained at a relatively high diffusion rate due to the presence of additional growth of metal precursors on the preformed metal nuclei, while at relatively low diffusion, the as-prepared noble metal nanoparticles are small and quasi-spherical due to the relatively fast reduction of metal precursors. The experimental observations are also confirmed qualitatively by kinetic Monte Carlo (kMC) simulations. Since diffusion and reaction kinetics are universal and key factors in the synthesis of nanomaterials, the findings in this work might provide an effective way to manipulate the morphology of nanomaterials for a given application.
研究领域:
纳米材料科学
·
物理化学
·
材料合成
·
胶体与界面化学
·
计算材料学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2017
·
IF 2.572
Shu-Hui Xia,Shu-Hua Teng,Peng Wang
Polyvinyl alcohol/silica (PVA/SiO 2 ) hybrid fibers were prepared via a sol–gel combined electrospinning technique, and their potential application in bone tissue engineering was evaluated in terms of in vitro bioactivity. When the PVA concentration was 8%, the obtained PVA/SiO 2 hybrid fibers exhibited a uniform and continuous morphology, with an average fiber diameter of about 542.9 nm. The SiO 2 xerogel phase was uniformly distributed within the PVA matrix, and its actual content was very close to the theoretical value. After 3 days of immersion in simulated body fluid (SBF), the PVA/SiO 2 hybrid fibers displayed a vigorous precipitation of lamellar apatite crystals, reflecting their excellent in vitro bioactivity.
研究领域:
生物材料学
·
组织工程
·
纳米医学
·
生物医学工程
·
无机非金属材料
·
再生医学
✓ 已验证
DOI
高影响因子
Arabian Journal of Geosciences
·
2019
·Vol. 12
·期 7
·256
·
IF 1.141
Li Weitao,Wei Falin,Xiong Chunming,Ouyang Jian,Zhao Guang,Shao Liming,Dai Mingli
Aiming at deep profile control in water flooding reservoirs, a heterogeneous combination flooding system, composed of dispersed particle gel (DPG) and a zwitterionic surfactant (THSB), was developed. The mean particle diameter was adjusted and then the DPG morphology and diameter were characterized using a laser scanning, confocal microscope, and dynamic light scattering. The effects of DPG concentration, temperature, pH, and salinity on THSB interfacial tension (IFT) were investigated. A method for determining DPG concentration was proposed, and the dynamic retention and migration mechanisms of the particles were evaluated, using cores with different permeabilities. Finally, the oil displacement mechanism of the combination flooding system was explored through visual simulation experiments and scanning electron microscopy. The results showed that the particle diameter was 2.5 μm, that compared with a surfactant system, the IFT of the combination flooding system was relatively low, and that the temperature, pH, and NaCl content of solutions had little effect on THSB IFT. Since specific matching relationships between DPG particles and reservoir pore throats existed, the retention amount and injection pressure were improved with the increased core permeability. Visual simulation experiments revealed the oil recovery mechanism of the combination flooding system. This combination flooding system can be used in reservoirs under varied conditions, as the particle diameter can be adjusted on a case-by-case basis, and the THSB surfactant proved to be high-temperature resistant and high-salinity tolerant. The combination flooding system can be applied to deep profile control and oil displacement, in oil fields.
研究领域:
石油工程
·
提高采收率
·
油田化学
·
渗流力学
·
油气田开发
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Weiyi Zhang,Haozhen Zhang,Xinglian Xu,Xue Zhao
The oil polarity was hypothesized to significantly influence the microscopic conformation of interfacial myofibrillar protein (MP) and thus the mesoscopic interfacial rheology of MP film , which ultimately tuned the macroscopic stability of MP-stabilized emulsions. In this research, the inner mechanism was revealed hierarchically based on emulsions multi-scale properties, by a combination of in vitro interfacial concentration measurement, dynamic interfacial tension measurement and interfacial dilatational rheology (highlighting Lissajous plots). Then, the above conclusion was verified through in silico molecular dynamic simulation. At macroscopic level, the light scattering results showed that emulsion prepared with higher polarity oil exhibited higher physical stability. This could be explained from the mesoscopic perspective that: (1) the adsorption dynamics of MP was faster (though lower diffusion rate, but higher penetration and rearrangement rate) on the higher polarity interface, which decreased interfacial tension more efficiently; (2) adsorption ratio, surface load and desorption ratio indicated that ‘multilayer interfacial film’ was formed by loosely-bound MP on the lower polarity interface, which decreased the effective interfacial coverage to impair emulsions stability; (3) Lissajous plots showed that interfacial structure with higher stability against large deformation was formed on the higher polarity oil interface. Finally, the microscopic molecular mechanism for explaining the above findings was revealed by in silico molecular dynamic simulation: though MP was less unfolded on the higher polarity interface leading to weaker intermolecular hydrophobic interactions, this compact molecular structure with stronger intramolecular rigidity predominantly contributed to steadier interfacial film structure. This multi-scale study provides a deep insight into the inner relationship between oil polarity and emulsions stability.
研究领域:
食品科学
·
胶体与界面化学
·
蛋白质构象
·
软物质物理
·
分子模拟
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）